The present invention relates generally to rotating machines such as automobile of the type including a stator and a rotor.
A vehicle alternator rotor comprising a shaft and two plates threaded onto the shaft and comprising interleaved pole horns and permanent magnets disposed in the spaces between the pole horns is known in the art. The magnets are held in place by a one-piece resin holding member that receives the magnets in housings and is disposed between the plates and between the pole horns, for example. This device has the drawback that it requires the various components of the rotor to be assembled in a particular order, namely the order such that the magnets are housed on the holding member and the plates are attached to respective opposite sides of the holding member. This order of assembly can be a constraint in relation to the organization of the assembly line. What is more, a large portion of the holding member is inside the rotor and between the magnets and the pole horns. It follows that the volume of the magnets and/or other parts of the rotor must be reduced, which reduces the performance of the alternator.
One aim of the invention is to provide a rotor of a different type, in particular one enabling a different order of assembly and preserving the internal volume of the rotor available for the magnets in particular.
With a view to achieving this object, the invention provides a vehicle alternator comprising a rotor including a shaft, two plates comprising interleaved pole horns, magnets lying between the pole horns, and magnet holding members, wherein the holding members face an outside axial end face of the plates.
The holding members are therefore adapted to be attached to the rotor in an axial direction of the rotor after the plates have been mounted. What is more, the portion of each holding member facing the outside axial end face of the plate does not extend into the interior of the rotor and the volume of the other parts of the rotor is therefore preserved commensurately.
The holding members advantageously face an outside circumferential face of the magnets.
The external support therefore preserves mere of the internal volume of the rotor than holding the magnets internally.
The holding members advantageously comprise lugs each adapted to face an outside circumferential face of two magnets.
Each lug advantageously comprises two plane parts separated by a bend parallel to an axis of the rotor.
The lug therefore takes account of the different inclinations of the two magnets about the axis of the rotor without complicating the fabrication of the lug.
Each lug advantageously has a notch at one end edge.
The notch houses the point of the pole horn facing the lug and the lug can therefore be made longer on both sides of the pole horn.
The holding members advantageously each include a flange facing one of the plates.
Each holding member advantageously has openings communicating with spaces under the magnets.
This allows air to pass under the magnets to cool the interior of the rotor.
The holding member are advantageously fixed directly to the plates.
The holding members are advantageously fixed to an outside axial end face of the plates.
The holding members are advantageously welded to the plates.
Each holding member advantageously extends continuously from one outside axial end face of the respective plates to the other.
The holding members advantageously comprise first members fixed to a first of the plates and extending along the magnets and second members fixed to the second plate and to the first members.
The second members advantageously cover,the first members in a radial direction relative to an axis of the rotor.
The first members advantageously cover the second members in a radial direction relative to an axis of the rotor.
The first and second members are advantageously each in one piece.
The holding members are advantageously made of bent plate.